SLACK; ON POND LIFE. 311 



Slack for all the details which he has presented to him in 

 this little book, and which the more dignified philosopher 

 might think almost entirely beneath his notice. What 

 really interests the great mass of the world is not the 

 advancement of science, but little peeps at the wonders of 

 nature, for which alone their limited or one-sided education 

 has fitted them. It is not because a man has been educated 

 at one of om* universities, that he requires for his delectation 

 in natural science short descriptions of natural objects in 

 Latin. No, he too must begin with the child ; and, if he 

 would learn the mysteries of organization, must take his 

 dipping-bottle to the pond side, and feel an interest, in com- 

 mon with Mr. Slack, in marvelling over the structures he has 

 thus secured. We shall not, therefore, attempt to be critical 

 on Mr. Slack^s volume, but express our welcome at the 

 heartiness with which he enters into microscopical work, and 

 the interest he has succeeded in throwing into his researches. 

 Of course, as his investigations were confined to fresh 

 water, the great mass of his observations are on the infusorial 

 animalcules and the rotifers. Here is his account of catching 

 one of the rarer forms of the last class : — 



" When the Floscules or other tubicolar rotifers are specially 

 sought for, the best way is to proceed to a pond where slender- 

 leaved water-plants grow, and to examine a few branches at 

 a time in a phial of water with a pocket lens. They are all 

 large enough to be discerned, if present, in this manner, and 

 as soon as one is found others may be expected, either in the 

 same or in adjacent parts of the pond, for they are gregarious 

 in their habits. With many, however, the first finding of a 

 floscule will be an accident, as was the case last April, when 

 a small piece of myriophyllum was placed in the live-box, 

 and looked over to see what it might contain. The first 

 glimpse revealed an egg-shaped object, of a brownish tint, 

 stretching itself upon a stalk, and showing some symptoms 

 of hairs or cilia at its head. This was enough to indicate the 

 nature of the creature, and to show the necessity for a care- 

 ful management of the light, which, being adjusted obliquely, 

 gave quite a new character to the scene. The dirty brown 

 hue disappeared, and was replaced by brilliant colours ; while 

 the hairs, instead of appearing few and short, were found to 

 be extremely numerous, very long, and glistening like deli- 

 cate threads of spun glass. 



" Knowing that the Floscules live in transparent gelatinous 

 tubes, such an object was carefully looked for, but in this 

 instance, as is not uncommon, it was perfectly free from 

 extraneous matter, and possessed nearly the same refractive 



VOL. I. — NEW SER, Y 



